As a woman, you know your risk of bone loss is far greater than that of a man. Your hormone levels fluctuate, and as menopause approaches you could suffer from osteoporosis, a condition that makes your bones extremely weak and brittle. Calcium and magnesium are minerals that primarily work to keep your bones as strong as possible. These minerals even go above and beyond this function to support hormonal, neurological and other biological processes. Dosage recommendations for calcium and magnesium vary depending on different stages of life.
Throughout your adult life, you need 1,000 milligrams of calcium daily, according to the Food and Nutrition Board at the Institute of Medicine. Even if you're pregnant or nursing, that amount doesn't change. But once you turn 51, you'll need to up your daily calcium intake to 1,200 milligrams, which is the level you'll need to maintain for the rest of your life.
Magnesium requirements vary a bit. During your 20s, you'll need 310 milligrams a day. This amount goes up to 350 milligrams daily if you're pregnant, then back down to 310 milligrams after delivery and while you're breast-feeding. Once you're in your 30s, you'll need 320 milligrams of magnesium each day, and you'll need to maintain that level for the rest of your life The only time this fluctuates is if you're over 30 and pregnant. In that case, aim for 360 milligrams a day, which you can drop back down to 320 milligrams while nursing.
Tolerable Upper Intake Levels
Most vitamins and minerals have a tolerable upper intake level, or UL for short. This amount, set by the Food and Nutrition Board at the Institute of Medicine, indicates how much of the nutrient you can safely take before possibly suffering from complications. Calcium has a UL of 2,500 milligrams daily, which decreases to 2,000 milligrams daily after age 50. The upper limit for magnesium applies to supplements only and is 350 milligrams per day, no matter your age. Note that for magnesium, the recommendation during pregnancy if you're over 30 is slightly higher than the supplemental UL, because it applies to dietary intake. Going over the tolerable upper intake level for either of these nutrients, which is usually the result of taking too much in supplemental form, can lead to digestive problems, vomiting and abnormal functioning of your vital organs.
Calcium supplements come in many forms, all of which are beneficial. However, your doctor will probably suggest that you take calcium carbonate. This type of calcium has the highest percentage of elemental calcium -- 40 percent -- which is the amount of calcium that is readily available for absorption. Another variety you can take is calcium citrate, but the citrate variety is only 21 percent elemental calcium. As with calcium, some varieties of magnesium have more elemental magnesium than others. Magnesium citrate, lactate, chloride and aspartate varieties tend to have more elemental magnesium than magnesium sulfate or oxide supplements. Read the label carefully; it should state exactly how much elemental magnesium is in the supplement you take.